Background
Inhibition of angiogenesis reverses rodent obesity. A validated assay in human fat tissue is needed to study the role of angiogenesis
in human obesity.
Methods
Human fat tissue fragments from surgery were placed in 96-well plates, embedded in fibrin thrombin clot and overlaid with
cell culture media containing 20% fetal bovine serum. After 15 days, the clots were examined by histology and electron microscopy.
The effect of taxol, cobalt chloride and a heparin-steroid combination was tested in the fat tissue assay and compared to
the validated human placental vein angiogenesis model (HPVAM).
Results
Blood vessels initiated growth and elongated from the fat tissue fragments over 15 days. Presence of blood vessels was confirmed
with histology and electron microscopy. Taxol at 10−6 and 10−7 M completely inhibited angiogenesis, while Taxol 10−8 and 10−9 M and the heparin-steroid partially inhibited angiogenesis.The response to taxol and heparin-steroid was similar to that
of the HPVAM, a validated angiogenesis assay. Cobalt chloride, a stimulator of vascular endothelial growth factor (VEGF) stimulated
angiogenesis initiation at 10−9 M in fat tissue and the HPVAM, but at 10−10 M blood vessel growth was stimulated only in the fat assay.
Conclusion
This angiogenesis assay based on human fat tissue uses three-dimensionally intact human tissue. The vessels are derived from
quiescient vessels within the fat. These properties allow the angiogenic switch to be evaluated in an in vitro setting. The
angiogenic response of fat tissue is not identical to placental tissue. This assay allows exploration of angiogenesis in fat
tissue.
Key words Fat - angiogenesis - assay - blood vessels - human